In general, failure analysis of an IC (Integrated Circuit) is being performed. The IC is fabricated by integrating a number of microminiature elements, such as a transistor, a diode, a resistor or a capacitor, on a substrate, and by electrically connecting or insulating the elements. In an IC package, a semiconductor chip is sealed with a mold, such as a resin. Hence, when a malfunction occurs in the integrated circuit formed on the semiconductor chip of the IC package, in order to conduct a cause analysis or to make a circuit modification, it is desired to remove the resin that seals the semiconductor chip so as to expose the semiconductor chip.
Therefore, conventionally, as a method for unsealing the IC package, the resin is removed by applying an acting medium, such as a nitric acid, with a jet flow on the resin mold that seals the semiconductor chip of the IC package. Also, dry etching or the like are used.
However, according to the conventional chemical solution method in which a solution is used to remove the resin mold so as to unseal the IC package, there is a problem of waste liquid treatment and corrosion of an apparatus. As for the dry etching, there is a problem that a processing speed is low. Further, because a position or an installed condition of the semiconductor chip sealed with the resin mold is unrecognized, there is a problem that, for example, the semiconductor chip is damaged in a removal process or the resin with which the semiconductor chip is covered cannot completely be removed cleanly.